The present invention relates to a semiconductor device, a battery state monitoring module, and a vehicle system, for example, to a semiconductor device for measuring a charge-discharge current of the battery based on a voltage difference that occurs between two ends of a current detecting resistance having a low resistance, a battery state monitoring module, and a vehicle system.
In the automobile, electric power used for engine start or various controls is provided by a battery. The storage battery is used for the battery carried on the automobile. The battery is charged by an alternator for generating electricity with an engine power. This battery has a feature that its characteristics deteriorate according to its duration of use. For example, the battery has a characteristic that as the duration of use becomes longer, a storage capacity falls, and an output impedance increases, and if such performance deterioration occurs, a problem that the vehicle does not operate normally will be arisen. Therefore, it is necessary to calculate a life of the battery based on a state of the battery, and to judge whether the battery satisfies required performance. Then, a technology of performing a voltage measurement of the battery that is one index of the performance of the battery is disclosed in Japanese Unexamined Patent Application Publication No. 2010-249793. In Japanese Unexamined Patent Application Publication No. 2010-249793, a voltage of each cell of multiple battery cells that are included in an assembled battery as a battery is measured. Here, Japanese Unexamined Patent Application Publication No. 2010-249793 is characterized in that a battery monitor device diagnoses whether a battery state detection circuit for detecting a battery state of a battery cell is operating normally by inputting pseudo voltage information to the battery state detection circuit based on the cell voltage. By Japanese Unexamined Patent Application Publication No. 2010-249793, reliability of a cell voltage measurement system can be improved by diagnosing the battery state detection circuit.